Imagination is not just replaying what we’ve seen and heard

brain scan: A technique to view structures inside the brain, typically with X-rays or a magnetic resonance imaging (or MRI) machine. With MRI technology — especially the type known as functional MRI (or fMRI) — the activity of different brain regions can be viewed during an event, such as viewing pictures, computing sums or listening to music.

component: Something that is part of something else (such as pieces that go on an electronic circuit board or ingredients that go into a cookie recipe).

default mode: A network of brain regions — one which becomes active when people daydream or try to understand what motivates the actions of others.

MRI: Short for magnetic resonance imaging. It’s an imaging technique to visualize soft, internal organs, like the brain, muscles, heart and cancerous tumors. MRI uses strong magnetic fields to record the activity of individual atoms.

network: A group of interconnected people or things.

neuron: The main cell type of the nervous system — the brain, spinal column and nerves. These specialized cells transmit information by producing, receiving and conducting electrical signals. Neurons also can transmit signals to other cells with chemical messengers.

neuroscientist: Someone who studies the structure or function of the brain and other parts of the nervous system.

psychologist: A scientist or mental-health professional who studies the mind, especially in relation to actions and behaviors. Some work with people. Others may conduct experiments with animals (usually rodents) to test how their minds respond to different stimuli and conditions.

recall: To remember.

spatial: An adjective for things having to do with the space where something is located or the relationships in space between two or more objects.

system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.